Device for generating an artificial constriction in the gastrointestinal tract

ABSTRACT

A device for generating an artificial constriction in the gastrointestinal tract comprises a band ( 1 ), which can be placed annularly about a particular portion ( 2 ) of the gastrointestinal tract, and, by means of a piston-cylinder unit ( 8 ), the size of the passageway opening ( 19 ) of the portion ( 2 ) of the gastrointestinal tract encompassed by the band ( 1 ) is variable, and the band ( 1 ), in the proximity of its first end ( 4 ), is connected with the cylinder ( 6 ) of the piston-cylinder unit ( 8 ). The band ( 1 ) is connected in the proximity of its second end ( 5 ) with the piston ( 7 ) of this piston-cylinder unit ( 8 ).

BACKGROUND OF THE INVENTION

[0001] a) Field of the Invention

[0002] The invention relates to a device for generating an artificial constriction in the gastrointestinal tract with a band, which can be placed annularly about a particular portion of the gastrointestinal tract, in which, by means of a piston-cylinder unit, the size of the throughlet opening of the portion of the gastrointestinal tract, encompassed by the band, can be varied and the band is connected in the proximity of its first end with the cylinder of the piston-cylinder unit.

[0003] b) Description of Related Prior Art

[0004] A device for generating an artificial constriction in the gastrointestinal tract is known for example in the form of a gastric band from EP 0 702 529 B1. The device comprises a band, which can be placed about the inlet of the stomach and which is developed with an inner hollow chamber extending longitudinally. For the closure of the band placed annularly about the inlet to the stomach, the band comprises a closure device with a first closure part, disposed on one end of the band and having an insertion opening, and a second closure part, disposed at the other end of the band, which can be introduced through the insertion opening and can be latched with respect to it. To constrict the cross section of the passageway of the throughlet opening of the band, and consequently of the inlet to the stomach, the hollow chamber of the band is filled with a filling medium, and the quantity of the filling medium depends on the desired passageway cross section. An injection port connected to the band is provided for filling the band with the filling medium. The injection port is implanted under the skin of the patient.

[0005] Apart from the development as a stomach band, a device of this type can especially also be developed as an anal band for the closure of an optionally artificial anus.

[0006] One problem encountered in such devices comprises that these, sooner or later in the course of their use, can leak, such that their function is no longer ensured. Surgical removal and replacement of this band is subsequently required, which is tied to a corresponding strain on the patient. Such leaks occur in practice especially in the diaphragm delimiting the band toward the throughlet opening. Such leaks can occur for example due to material fatigue in the course of use or due to overfilling of the band. For so-called “early” leaks, which occur up to approximately one year after the placement of the band, injuries are most often responsible, which have occurred through a surgical instrument during the operative, in particular laparoscopic, placement of the band.

[0007] A device of the type described in the introduction is disclosed in U.S. Pat. No. 6,470,892 B1. The band here comprises a core encompassed by a tube. In one embodiment example a piston-cylinder unit is provided, whose cylinder is disposed at one end of the band and whose piston is connected with a traction cord to the core, which terminates at a distance from this end of the band. By displacing the piston, the core within the tube is displaced relative to it, whereby the band closed annularly via a closure, is drawn together. Of disadvantage in this band is inter alia its relatively complicated structure.

AIM AND SUMMARY OF THE INVENTION

[0008] One aim of the invention is providing an improved device of the type described in the introduction, in which the frequency of surgical interventions following implantation of the device is low. A further aim of the invention is providing a simple and advantageously implemented device of the type described in the introduction.

[0009] According to the invention this is achieved through a device for generating an artificial constriction in the gastrointestinal tract with a band, which can be placed annularly about the particular portion of the gastrointestinal tract, and a piston-cylinder unit to change the size of the throughlet opening of the portion of the gastrointestinal tract encompassed by the band, the band being connected in the proximity of its first end with the cylinder of a piston-cylinder unit and, in the proximity of its second end, with the piston of this piston-cylinder unit.

[0010] Consequently, in a device according to the invention the diameter of the band can be varied by means of the piston-cylinder unit. For this purpose the piston is displaced in the cylinder chamber of the cylinder. For example, this displacement can be accomplished by supplying or removing hydraulic fluid through an injection port. As the hydraulic fluid can be considered in particular sterile water, conceivable and possible would also be other hydraulic fluids well tolerated by the body.

[0011] Further advantages and details of the invention will be explained in the following in conjunction with the embodiment example of the invention depicted in the enclosed drawing, based on which are also evident additional aims of the invention.

BRIEF DESCRIPTION OF THE DRAWING

[0012] In the drawing depict:

[0013]FIG. 1 view of an embodiment example of a device according to the invention,

[0014]FIG. 2 side view of the embodiment example of FIG. 1, and

[0015]FIG. 3 side view partially in section along line AA of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT EXAMPLES

[0016] The embodiment example of a device according to the invention and depicted in the figures, is developed as a gastric band and comprises a band 1 to be placed annularly about the corresponding portion 2, shown schematically in FIG. 2, of the gastrointestinal tract, here the stomach, the inlet to the stomach or the esophagus. The band 1, or at least its major portion, is comprised of a foamed material, preferably a foamed silicone material. In the region of its outer surface 3, facing away from the portion 2 of the gastrointestinal tract, the band 1 can be provided with a reinforced backing, for example of solid silicone, connected with the foamed material body, this reinforced backing can extend over the length of the band 1 or at least a large portion of this length (not shown in the figures).

[0017] The band 1 has a first end 4 and a second end 5. In the proximity of the first end 4 of band 1 the cylinder 6 of a piston-cylinder unit 8 is disposed on this band 1. In the embodiment example depicted the cylinder 6 is nondetachably connected with the band 1 in the proximity of the outer surface 3 of the band 1, it is for example adhered on or the material of band 1 is partially injected around it during its production.

[0018] In the state of the band 1 in which it is placed about the portion 2 of the gastrointestinal tract, moreover, a connection is formed between band 1 in the proximity of its second end 5 and the piston 7 of the piston-cylinder unit 8. For this purpose, in the depicted embodiment example on piston 7 a piston rod 9 is attached, at whose free end a first closure member 10 is disposed, which, in the drawing, is depicted schematically as a hook-like element. This first closure member 10 cooperates with a second closure member 11 secured in the proximity of the second end 5 of band 1, which second closure element is depicted in the figure schematically as a platelet-shaped part with an insertion opening for the hook-like first closure member 10. The closure members 10, 11 together form a closure device 12, by means of which the band in the proximity of its second end 5 can be attached on the piston rod 9. Instead of the formation of this closure device 12 depicted in the figures, different other formations would be conceivable and possible, for example in the form of snap closures, which can be developed such that they are detachable again after they have been closed or nondetachable after their closing.

[0019] When this application describes that the connection of the band with the cylinder 6 or the piston 7 takes place in the “proximity of the first or second end”, it is intended to indicate that the corresponding connection sites with the band are located either directly on the corresponding end of the band or are spaced apart from the particular end 4, 5 of the band by less than one fourth of the longitudinal extent of the band 1. At least one of these connection sites is preferably spaced apart from the corresponding end 4, 5 of this band 1, such that a projecting segment 13, 21 results. In the depicted embodiment example such projecting segments 13, 21 are disposed at both ends 4, 5, which are formed for example by end pieces of nonfoamed (solid) silicone connected, for example adhered, to the foamed material body forming the remaining length of the band 1. When the two closure members 10, 11 of the closure device 12 are connected with one another, segments of band 1 adjoining the two ends 4, 5 overlap when viewed in the circumferential direction, such that band 1 forms a closed ring viewed in side view. Depending on the position of piston 7 in cylinder 6, this overlap increases or decreases, whereby the diameter of the ring increases or decreases.

[0020] For forming this overlap, in the depicted embodiment example a recess is developed in band 1 starting from the second end 5 or projecting segments 21 of band 1. The projecting segment 13, which forms the first end 4, is of lesser width than the width of this recess and, depending on the position of piston 7, projects to a greater or lesser extent into this recess.

[0021] Various other developments of such an overlap of the two end regions of the band, viewed in the circumferential direction, are conceivable and possible. For example, the band 1 in the region of its two ends 4, 5 could comprise segments, whose width is decreased to approximately one half the value of the remaining band, these segments being offset with respect to one another when viewed in the direction of axis 22 of the throughlet opening, and disposed one next to the other in the overlapping region. It would also be conceivable and possible, that a projecting segment at one end of the band overlaps the other end of the band radially within it, and consequently is in contact on a segment, adjoining this other end of the band, on the inner surface 20 of the band 1. This projecting segment in contact on the inner surface 20 of the other end segment of the band could be developed approximately in the form of a wedge forming only a small step on the inner circumference of the band.

[0022] The piston-cylinder unit 8 is connected to an injection port 17 via a tubule 14, whose inner channel 15 communicates with the cylinder chamber 16 of the piston-cylinder unit 8. Consequently, the device includes an inner volume, which is formed by cylinder chamber 16, channel 15 and the inner chamber of injection port 17 and is filled with hydraulic fluid, for example sterile water. To change the position of the piston 7 within the cylinder chamber 16, the quantity of hydraulic fluid present in this closed inner volume is changed. For this purpose, the injection port 17 comprises a diaphragm 18 which can be pierced by the needle of a syringe. By means of the needle inserted through the skin of the patient into the diaphragm of the implanted injection port, the hydraulic fluid can be injected into the inner volume of the injection port or be withdrawn from it. After the needle of the syringe has been withdrawn, the relatively thick diaphragm 18 closes tightly again. Such injection ports are known.

[0023] For placing the band 1 about portion 2 of the gastrointestinal tract, for example in a laparoscopic procedure, the second closure member 11 disposed in the proximity of the end 5 of band 1, is initially not connected with the first closure member 10. Using a surgical instrument, the band is pulled by its second end 5 about portion 2 of the gastrointestinal tract and the second closure member is subsequently connected with the first closure member 10 disposed on the piston rod 9. The band 1 now annularly encompasses portion 2 of the gastrointestinal tract, as is shown schematically in FIG. 3. To decrease the size of the passageway opening 19 of portion 2 of the gastrointestinal tract to the desired value, the band 1, starting from the condition depicted in the figures, is correspondingly drawn together by means of the piston-cylinder unit 8, whereby the end segments of the band increasingly overlap and the diameter of the band is decreased.

[0024] Instead of introducing or withdrawing hydraulic fluid into or from the closed inner volume of the device by means of an injection port, which, in this sense, forms an hydraulic actuation unit for the piston-cylinder unit 8, it would also be conceivable and possible to connect the tubule 14 with its end, facing away from the piston-cylinder unit 8, with an hydraulic actuation unit, which has a variable inner volume. If the device is developed as an openable and closable closure, for example as an anal band, the hydraulic actuation unit would need to be switchable in known manner between two sizes of its inner volume corresponding to the closed and opened condition of the device.

[0025] Different modifications of the depicted embodiment example of the invention are conceivable and possible without going beyond the scope of the invention. For example, the piston rod 9 could also be nondetachably connected, for example adhered on or injected, with the band 1 in the region of its second end 5, and the cylinder 6 could be connectable with band 1 via a first closure part, disposed on cylinder 6, and a second closure part, disposed on band 1 in the proximity of its first end 4.

[0026] After both closure members 10, 11 have been connected with one another, the device is advantageously developed such that the inner circumference, facing portion 2 of the gastrointestinal tract, of band 1 is substantially stepless or has only minimal steps, the material of band 1 being relatively soft in the proximity of optionally provided steps (in particular in the region of overlap of the two end segments).

Legend of reference numbers

[0027]1 Band

[0028]2 Portion of the gastrointestinal tract

[0029]3 External surface

[0030]4 First end

[0031]5 Second end

[0032]6 Cylinder

[0033]7 Piston

[0034]8 Piston-cylinder unit

[0035]9 Piston rod

[0036]10 First closure member

[0037]11 Second closure member

[0038]12 Closure device

[0039]13 Projecting segment

[0040]14 Tubule

[0041]15 Channel

[0042]16 Cylinder chamber

[0043]17 Injection port

[0044]18 Diaphragm

[0045]19 Passageway opening

[0046]20 Inner surface

[0047]21 Projecting segment

[0048]22 Axis 

1. Device for generating an artificial constriction in the gastrointestinal tract with a band (1), which can be placed annularly about a particular portion (2) of the gastrointestinal tract, and a piston-cylinder unit (8) for varying the size of the passageway opening (19) of the portion (2) of the gastrointestinal tract encompassed by the band (1), the band (1) being connected in the proximity of its first end (4) with the cylinder (6) of a piston-cylinder unit (8) and, in the proximity of its second end (5), with the piston (7) of this piston-cylinder unit (8).
 2. Device as claimed in claim 1, in which the position of the piston (7) is variable relative to the cylinder (6) of the piston-cylinder unit (8) by means of a hydraulic actuation unit (17) connected with the piston-cylinder unit.
 3. Device as claimed in claim 2, the hydraulic actuation unit (17) being an injection port (17) connected via a tubule (14) with the cylinder chamber (16) of the piston-cylinder unit (8).
 4. Device as claimed in claim 1, in which on the piston (7) a piston rod (9) is disposed, via which the piston (7) is connected with the band (1) in the proximity of its second end (5).
 5. Device as claimed in claim 1, in which, for the connection of the band (1) with the cylinder (6) of the piston-cylinder unit (8) or for the connection of the band (1) with the piston (7) of the piston-cylinder unit, a closure is provided, which can be closed, after the band has been placed with the closure open about the particular portion (2) of the gastrointestinal tract.
 6. Device as claimed in claim 5, in which, for the connection of the band (1) in the proximity of its second end (5) with the piston (7) or the piston rod (9) disposed on the piston (7), a first closure member (10) is disposed on the piston (7) or on the piston rod (9), which can be connected with a second closure member (11) disposed on the band (1) in the proximity of the second end (5) of the band (1).
 7. Device as claimed in claim 6, in which the cylinder (6) of the piston-cylinder unit (8) is nondetachably connected with the band (1) in the proximity of its first end (4).
 8. Device as claimed in claim 5, in which for the connection of the band (1) in the proximity of its first end (4) with the cylinder (6) a first closure member is disposed on the cylinder (6), which is connectable with a second closure member disposed on the band (1) in the proximity of the first end (4) of the band (1).
 9. Device as claimed in claim 8, the piston (7) being nondetachably connected with the band (1) in the proximity of its second end (5).
 10. Device as claimed in claim 1, the band (1) being comprised at least substantially of silicone.
 11. Device as claimed in claim 5, in which with both closure members (10, 11) connected with one another, segments of the band (1), adjoining both ends (4, 5) of the band (1), overlap when viewed in the circumferential direction, the band (1) forming a closed ring viewed in side view.
 12. Device as claimed in claim 11, in which at one end (5) of the band a recess is developed, extending starting at the end (5) of the band in the circumferential direction of the band (1), into which projects a segment of the band (1) adjoining the other end (4) of the band (1).
 13. Device as claimed in claim 1, in which at least in the proximity of one of the ends (4, 5) of the band (1) a projecting segment (13, 21) is provided extending in the direction toward the corresponding end (4, 5) starting at the connection site of the cylinder (6) on the band (1) or starting at the connection site of the piston (7) on the band (1). 